QUANTIFICATION OF ENVIRONMENTAL. IMPACTS

Abstract

Main objective of this study was to develop and apply methods for quantification of some important environmental impacts of a river valley project. Baseline information for the Jatigede dam on Cimanuk River in Indonesia has been collected for application of the selected methods. The study covers the following: 1. Review and comparison of country practices on EIA in Indonesia, India and developed countries. 2. Application of universe soil loss equation for estimation of soil erosion and as a tool to identify measures for managing soil erosion within tolerable limits. 3. Application of indices to quantify biodiversity, stress of sediment flushing on aquatic biota and severity of noise pollution. 4. Development and application of principles of resettlement. 5. Design of a preliminary EIA simulation exercise and its application. Available literature on EIA practice followed in various countries has been studied. Annexure 1 and annexure 2 provide review of practice followed in Indonesia and India respectively. Comparative review of EIA procedures and practices in different countries (EIA legislation, involvement of participants, integrated approach, consideration of alternatives, screening, scoping, language of reports, expertise etc) have been made. Two simple indices to measure species-level biodiversity are Simpson index and Shannon&Wiener index. These indices have been applied using data on phytoplankton, zooplankton and benthos composition at 13 sites on Cimanuk River (figure 4.2) for dry season (August and September) and wet season (November and December). Impact of flushing of sediment on aquatic organisms has been assessed using suspended sediment stress index. The data for Cimanuk River is not available for calculation of Stress Index. For illustration, the data of Bengawan Solo River (Central Java) has been taken. iii Noise pollution index has been used to assess noise pollution level due to the heavy machines during construction. Erosion rates (potential, under existing land use and with possible management measures) have been evaluated (chapter 5). It is shown that the erosion rates can be significantly lowered with proper land use management in upper catchments. It is suggested that erosion measures should be immediately started with or without a dam as this non-structural measure will contribute to flood control in lower reach. Jatigede dam is a multipurpose reservoir. As the actual data for the Jatigede area is not available, analysis of resettlement alternatives could not be carried out. However a procedure which is scientific and reliable has been worked out for analysis of resettlement requirements and development of resettlement plan. A simulation exercise for learning EIA process has been developing. This exercise is based on the knowledge gained at IIT Roorkee and available literature on EIA practices in India. The simulation exercise illustrates stepwise procedure in a simplified manner and is useful in comprehending the scope of EIA as well as in explaining the concepts and procedures. It is hoped that this study shall lead to further refinement in methodology for quantification of various impacts and shall be useful for adopting appropriate mitigation measures.